* @param cancelCommand the command to trigger on cancel.
*/
@Override
public void update(Throwable error, Command errorCommand, Command cancelCommand) {
this.error = error;
this.errorCommand = new CurrentDocumentRefreshCommand(false, errorCommand);
this.cancelCommand = cancelCommand;
this.messagePanel.clear();
this.messagePanel.add(new HTML("A different and recent version of the current document exists in the Google Docs servers.<br />" +
"You may choose to continue and apply the pending changes to the version at the server or reload the document.<br />" +
"Reloading the document will cause any unsaved changes to be lost."));